A coding scheme was developed in a directed content analysis [33]: First a literature review identifying key reasons for not seeking treatment was performed to generate the basic coding scheme. Then all answers on the open ended question were read to identify meaningful subcategories and include reasons not yet covered by the basic coding scheme. After coding a sample of 100 answers the authors discussed and adapted the scheme where necessary to capture all reported reasons. The coding scheme (see Additional file 1: Table S2) was then applied independently by two raters. All cases of non-agreement were revisited and discussed between the authors to come to a final decision.
